Dry-charged battery plate



v charged condition.

Io Drawing.

Patented Mar. 11, 1930 UNITED. STATES PAT NT oFmcs SCOTT HUTGEINSON, OI SOABSDALE, NEw YORK, ASSIGNOB, BY DIRECT AND HESNE ASSIGNMENTS, TO THE SILICA GEL CORPORATION, or BALTIIOBI,

IABYLAND, A-COBIBORATION OI MARYLAND DRY-CHARGED BATTERY PLATE irom the time of immersion of the plates in the electrolyte. When the negative plates have just been formed or developed the so-called active material or pasteo the plate consists largeefiliy of pure sponge lead with a littlelead I hate. On beingtaken outofthe forming bath and exposing to the air they oxidizerapidly and the acid adhering to the plate forms lead sulfhate so that a skin is formed across the sur ace of the plate. When such negative plates aresubs'equently assembled with the positive plates and the electrolyte added'the charge is not available and for. all

useful urposes they are not in a state of charge ut require a considerable current or may be said to be charged in any useful sense.

The demand for a dry charged battery plate, especially a negative, has brought about a number of endeavors to 1produce such a plate which would be availab e practically at once upon the assembly of the plates and addition of the electrolyte. Amon these may be mentioned the use of formalde yde or other neutral gases in which the plates are dried so as to avoid oxidation as above referred to.

So far as I am aware all of these efiorts have been in connection with ne ative plates which I believe is caused by t e fact. that .when the positive plate is charged lead peroxide is formed, which does not oxidize, so

that it has been considered sufiicient to simply washthe acid-off the plate.

According to the present inventionit is proposed to stabilize the charged-plate b treating it with an absorptive material whic absorbs liquid from the plate and also acts to exclude the air sufiioiently so that no intolerable amount'of oxidation of the plate may take place. As an example of carrying out the inventionnegative plates formed and charged in the usual way are taken from Application fled. m 1:,

. tive 1m. main. 43,405.

the electrolyte and washed with water toremove all acid etc. These plates are' then placed in a container either singly or in groups and covered with granulated silica lgel which substantially removes the moisture y absorbing it. The absorption of the water by the gel causes considerable evolution of heat WhIOh assists the expulsion of the water from the plate and its absor tion by the gel. e action is even improves by heating the gel. y

e the negative plate has n more particularly referred to it has been found that the same method of treatment as re ferred to 'ves a ve much improved plate when app ied to positive plates. The positive plates thus treated have been very much better than those which;are dried in the air or treated in other known ways. The posilates thus treated 've very much better resu ts when a's'sembl with the charged negatives and electrolyte than do the positives not so treated.

Another material which I may use in place of silica gel in the process above referred to, as an absorptive material is dry wood sawdust. Also good results maybe obtainedby using as a porous absorptive material calcium, sul hate or sum ground to the desired e of eness. Also lime, dry slacked hme or hydrous aluminum oxide,de hydrated bauxite, dried cereals and other materials mi ht be used. It is thus a parent that'adsor nts and absorbents ma be used in practicing my invention. I pre er to use .adsorbents, and specifically silica gel. The

absorlptive which haveftheability to take up liqui from the treated plates. Many substances not naturally porous may be made absor tive by powdering or granulating where y the interstices between the parti cles act as-absorptive' pores. The material to take u the liquid or absorptive material should grounder otherwise reduced to a condition of small particles. This is of benefit because, within limits, the smaller interstices produce more efiicient absorption and the absorptive mass is more compact so that the air is more completely excluded from the plate. Care should be taken, howeyer, that the material is not too fine a powder as it may then stick to the plates. This is avoided by the use of coarser particles which may be referred to as granulated. While it is beliei ed that this condition produces the most eflicient results, the invention may be availed of to a great extent under other conditions. The term gel as used in the specification and claims refers to a hard porous material. .One method of preparing it is described in Patent No. 1,297 ,724.

While the invention has been set forth in what is considered its best illustrations the details of the. process maybe varied without departing from the spirit of the invention,

it'is not, therefore, limited to theprecise details of method as recited. What Iclaim is; 1 1. The method of preparing for-,storage and shipment a formed storage "battery plate which comprises contacting thev active material of the plate with a solid adsorbent ma-' terial .capable of adsorbing the liquid, the said material being of such character as-not to stick to the plate. I r

2. The method, of preparing for storage and shipment a formed storage battery plate which comprises contacting the active ma- P terial of the plate with an adsorptive'gel capable of adsorbing the liquid.

3. The" method according to claim 2 wherein the material is aIsilica gel. 1' 4. The method according to claim l wheree I 'in the contact is afiected at an elevated temperature.

5. The method of preparing for storage and shipmenta storage battery plate which comprises charging the plate, ,andth'en con-' tactin the active material of the plate with a $011 adsorbent material, the said material being of such character as not to stickto the plate.

The methodaccording to claim. 5 here'- m the material is a'silica gel.

7 .The method'of preparing tor storage and sh pment storage'battery plate which comprises washing the plate after charging thesame, to remove the electrolyte, and then contacting the. active material of the "plate with a solid adsorbent material capable of ad sorbing liquid, the said material beingof such character asnot to stick to the plate.

"contacting the active materialv of the plate '8. The method of preparing for storage and shipment a storage battery'plate which comprises washing the plate after; charging the same to remove the electrolyte','and then with silica gel. I L

'9. The method of preparing a wet charged battery plate that will not'o'xidize or sulphate to any substantial extent, so that substantiaL.

contacting the 1y .all of its charge is available after storage or shipment, which comprises contacting the active material of the plate with granular sorbent material.

. 10. The method of preparing a wet charged battery plate that will not oxidize or sulphate i to any substantial extent, so that substantially all ofits charge isavailable after storage or shipment, which comprises contacting the ac-i tive material of plate with granular adsorbshipment, which comprises contacting the active material of the plate with granular-sihca el. g 12. The method according to claim 9 wherein the'plate treated is a negative plate. .13. The method according toclaim 10 wherein the plate treated is a negative plate.

'14. The method according to claimlll wherein the plate treated is a negative late.

15'. The method according to claim 9 w erein the plate treated is a' lead-sponge late.

'16; The method according to c aim -10 wherein th plate treated is a lead-sponge plate.- v

' 17. The method according to claim 11 wlherein the plate treated is a lead-sponge ate. 18. The method of preparing a charged battery plate that will not oxidize or sulphate to any-substantial extent, so that substantially all of its-charge is available after storage or shipment, whi'chcomprises washing the elec+ trolyte therefrom with water, and then contacting the active material of the plate-with sorbentmaterial. a 19. The method of preparing a charged batbattery plate that will not oxidize or sulphate to any substantial extent, so that substantially all of its charge is available after storage or shipment, which comprises washing the electrolyte therefrom with water, and then active material of the plate with silicagel. 21. *The method according to claim 18 wherein the plate treated is a negative plate. 22. The method according to claim 19 wherein the plate is a negatiye plate. u

tery plate that will not oxidize or sulphate to 20. The method of preparinga. charged 23.- The method according to claim 20 wherein the plate treatedis a negative plate. '24. The method according to claim 18 wherein the' late treatediis a. lead-sponge plate.

26. The method according to claim 20 wherein the plate treated is a lead-sponge plate specification this 9th da WILLIAM SCOT In testimony whereof I have signed this of July, 1925. HUTCHINSON. 

